Deluge or preaction pressure tank sprinkler system with secondary supply



July 4, 1944. H. N. RIDER I ,353,117

DELUGE OR PREACTION PRESSURE TANK SPRINKLER SYSTEM WITH SECONDARY SUPPLY Filed July 13, 1942 5 Sheets-Sheet l v Q m h E N Q: I an III-null!!!" ||m|iil M x a N N I I i i slllll I attorney 'H.-N. RIDER I ,353,117 DELUGE 0R PREACTION PRESSURE TANK SPRINKLER SYSTEM WITH SECONDARY SUPPLY Filed July 13, 1942 5 Sheets-Sheet 2 Jul 4, 1944.

'IIIIIIIIIIIIIIIIIII n Z v Ismaentor (Ittorneg July 4, 1944. I RIDER 2,353,117 7 DELUGE OR PREACTION PRESSURE TANK SPRINKLER SYSTEM WITH SECONDARY SUPPLY Filed July 15, 1942 5 Sheets-Sheet 5 Snventor 5 EI/er (lttorn'eg J y 1944; H.\N. RIDER 2,353,117

I DELUGE 0R PREACTION .PRESSURE TANK SPRINKLER SYSTEM WITH SECONDARY SUPPLY 4 Filed July 13, 1942 v 5 Sheets-Sheet 4 Zmnentor Bu I I (Ittomeg July 4, 1944.

DELUGE OR PREACTION PRESSURE TANK SPRI NKLE H. N. RIDER 2,353,117

SYSTEM WITH SECONDARY SUPPLY I Filed July 13, 1942 5 Shee'ts-Sheet 5 Qttorneg Ennentor Patented July 4, 1944 ssPATEN DELUGE R PREACTlDN PRESSURE TANK SPRINKLER SYSTEM WITH SECONDARY SUPPLY Harry N. Rider, Youngstown, Ohio, assignor to Automatic? Sprinkler Company of America Youngstown, Ohio, a corporation of Delaware Application July '13, 1942-, SerialNo. 450,660 4 Claims. (01. 1699) This invention relates to a sprinkler systemdesigned for furnishing protection to buildings or other enclosures located in areas where there is no city water supply available or where the city watersupply is undepenclable' and is intended for occupancies that are not rated as hazardous risks or Where a limited volume of fire extinguishing fluid may well be' expected to control such fires as may break out. v

The principal object of this invention is the provision of a preaction sprinkler system incorporating a pressure tank as a primary source of water supply also provided with means for bringing into connection with the sprinkler system any auxiliary water supply that may be available such as a private water supply source.

A further object of the invention is the provision of a preaction sprinkler system wherein the primary water supply source comprises" a pressure tank wherein pressure developed in the tank results from the automaticrele'ase of compressed gas thereinto.

A still further object of the invention is the provision of'a preaction pressurejtank sprinkler system capable of adaptation so asto form a, deluge sprinkler system.

A still further object of the inventionis the provision of a preaction or deluge pressure tank sprinkler system adapted to make use of an auxiliary water supply and adapted to be placed in operation by a system of heat actuated devices located within the area protected by the sprinkler system. v 'The preaction or deluge sprinkler system, the subject of this invention, comprises a conventional preaction or deluge sprinkler system such as is well known in the art utilizing eitherfused or open sprinklers and having as its primary source of watersupply a tank in which pressure of expanded compressed gas released thereinto serves to force the fluid through the sprinkler system so as to control a fire. In addition thereto, a connection, controlled by an automatically which will appear as thedescription proceeds,

' ing drawings, wherein Figure 1 is 'a side elevation with parts broken away showing' the' complete organization of the deluge or preaction pressure tank sprinkler system with auxiliary water supply and actuating means dependent upon heat actuated devices.

on lines in Figure 5.

Figure 2 is an elevational view, partly in-cross section, of the auxiliary supply valve andactuating devicethereof illustrated in Figure 1.

s Figure, 3 is a cross sectional side elevation taken on lines 33 of Figure 2..

Figure 4" is ajgreatly enlarg'ed'side elevation with parts in cross section illustrating one of the 'heat actuated devices used in actuating the sprinkler system illustrated in Figure 1.

Figure 51'is1 aside elevation partly in cross section on the line 55 of Figure 6il1ustrating a mercury assembly optionally used with the sprinkler system illustrated in Figure 1'. I v

Figure 6 is a cross sectional illustration taken .Figure 7' is an enlarged cross sectional elevation of apneumatic impulse originating device shown in Figure}. l I

Figure 8 is an elvational view, partially in cross section, of a modified form of auxiliary supply valve and actuating device thereof.

The deluge orp'reaction pressure tank sprinkler system with auxiliary supply set forth herein, constitutes an improvement to that shown and I described in Patent No. 2,277,873 of March 31,

actuated valve, establishes communication with such auxiliary water supply as may be available and which may comprise a city Water connection or a private water system which my include an elevated tank or other water reservoir.

Specifically, the principal novelty of invention resides in the sprinkler system, its actuating system of heat actuated devices and the combination therewith of primary and secondary water supply sources and the means of bringing the same into active operation.v

With theforegoing and other objects inview so I 1942, on Pressure tank sprinkler system.

By referring to the-drawings and Figure l in particular, it will beseen that a sprinkler system patterned, onconventional lines and comprising a riser [0 provided with distributing pipes II which are in turn equipped with sprinklers 12,

either of the open orclosed type, has'been' designed'to furnish fireprotection to various en.- closures or buildings and that'thesame is, as

illustrated in Figurelgprovided with two sources of fluid supply; the primary source. comprising a pressure tank I3 adaptedto contain j'afsufiicient quantity of fire extinguishing fluid such. as water. tosupply the demands of the sprinkler system connection I1 at such time as a fire breaks out in the area protected by the said sprinkler system. The compressed gas conveying tubular connection I1 communicates with the pressure tank I3 by Way of a fitting I8, 9, safety plug I9, being provided in the pipe I1 to prevent the application of undue pressures to the pressuretank I3. The fitting I8 also communicates with a pneuthe pneumatic impulse originating device here tofore described as being in communication with the compressed gas conveying connection I1.

In order that the pressure tank I3 can be drained or refilled, a suitable fitting is provided and is indicated in Figure 1 by the numeral 33.

By referring now to Figures 2 'and 3 of the drawings, a detailed illustration of the auxiliary supply valve 23 and its actuating device 24 may be seen. By referring to Figure 2 in particular, it will be seen that the auxiliary supply valve 23' comprises a body member indicated by the numeral 23 in which a water inlet is indicated at 3.4. In order that the water inlet 34 may be successfully separated from the remainder of the valve body, an annular shoulder 35 is provided with a seat ring 36 adapted to receive a clapper matic impulse originating device generally indicated by the numeral 29 which device is illustrated in Figure 7 and described in greater tail herein. 7

In order that the sprinkler'system may be brought into operation in controllinga' fire, a system of heat actuated devices, either pneumatic or electric; a pneumatic device being indicated by the numeral 2I, is located in the area protected by'the' sprinkler system. The pneumatic heat actuated devices, which are well known in the art, originate a pneumatic impulse upon an abnormal increase in the temperature of the air surrounding them. The pneumatic impulse is conveyed by means of pneumatic impulse conveying tubing 22 to the gas release: mechanism I6 and may or may not be subject to passage through a system of mercury checks which form an optional part of the gas release mechanism I6 and which serve to'eliminate weak impulses and thereby prevent the undesirable actuation of the sprinkler system'in response to such weak impulses. The mercury checks are illustrated in Figures 5 and 6" of the drawings and described in detail herein,

In order that an adequate amount of fire ex-v line 25 and is indicated by the numeral .28. A: primary gate valve is positioned in the pipe connection I4 communicating With the pressure tank I3 and the same is indicated by the numeral 21.

Check valves 28 and 29 are positioned in the portion of the riser I'll above the automatic valve 23 and in the tubular connection I4, respectively, and serve to prevent the flow of fire extinguishing fluid in a direction other than that leading to the piping II and sprinklers I2 of the system. This arrangement of check valves is such that water is supplied to the riser-I0 from the source having the higher pressure. Also in communication with the riser I0 there is a fire department connection 30 incorporating a check valve 3i through which water may be pumped. The automatic valve 23 with which the riser IU' com municates, is, together with its actuating mechanism 24, illustrated in Figures 2 and 3' and dethat a tubular connection 32 connectsthe actuating portion 24 of the automatic valve 23 with 31 which serves to control the admission of fluid into the valve body from the Water inlet 34. A suitable rubber facing 38 is afiixed to the clapper 31 by means of a clamping ring 39 which is in turn. affixed to the clapper 31 by means of a plurality of bolts. The clapper 31 is formed with a pair of hinge arms 40 adapted to pivot about a hinge pin 4| so as to hinge the clapper in re lation thereto. The hinge pin M is carried on suitable bosses positioned in the valve body 23. In order that the clapper 31 will remain in closed position on the fluid inlet 34 and thus prevent the entrance of fluid from the auxiliary supply source 25, a latch mechanism is positioned within the valve body and adjacent to a shoulder 42 formed on the clapper 31. The latch mechanism comprises a latch 43 pivoted to the valve body by means of a pivot 44 so that horizontal movement in a counter-clockwise direction imparted to the lower end of the latch 43 results in moving it from its seat on the shoulder 42 of the clapper 31 thus effectively releasing the clapper 31 and permitting fluid in the fluid inlet 34 to raisethe clapper 31 and flow through the valve into the riser II It will be seen that the latch 43 has an antireseating portion 45 pivoted thereto and adapted to prevent the clapper 31 from reseating. A spring 46 serves to position the antireseating latch 45 in operative relation to the clapper 31 at all times. The non-reseating latch 45 is held in operative position by means of the spring 46 which is positioned about the pivot 44, The clapper 31 moves the non-reseating latch 45 upwardly in order to swing past the same when it opens. The spring 46 about the pivot 44 will return the non-reseating latch 45 to the position shown in Figure 2 so that the clapper 31 will come'into engagement therewith and be incapalatch 43 by means of a pin, 48, the latch link 41 passes centrally through and is affixed to a latch" link diaphragm 49 which is positioned in a Water tight manner across an opening 50 in'the valvebody 23. The latch link 41 passes through an opening in the diaphragm 49 and is affixed therein in a Water tight manner. A portion of the latch link 41 extends outwardly therefrom and forms a T shaped bracket 5| which is adapted to receive movement imparted thereto by a pair of latch arms 52 which are part of the valve actuating mechanism 2'4. The valve actuating mechanism 24 comprises a vertically positioned box bolted to the Valve body 23 so that the mechanism therein may efiectively impart movement to the latch 43. The latch arms 52 are pivoted,

to the actuating mechanism 100x24 by means'of a pivot 53 and are adapted .to impart movement to the latch link 41. In order that the'latch arms 52 may receive movement so as to actuate the latch 43, the outermost ends 54 thereof are pivoted by means of a pin 55 to the lowermost end of a vertically positioned guide rod 56.

7 By referring now to Figure 3 of the drawings, it will be seen that the uppermost end of this guide rod 56 is slidably positioned within a bushign 51 which is in turn carried by the vertically positioned mechanism box 24. It will be seen that a bumper 58 is provided beneath the latch arms 52. A secondary guide rod 59 is'positioned vertically adjacent the guide rod 56. Still referring to Figure 3 of the drawings, it will be seen that an actuating weight 66 is slidably positioned upon the guide rods 56 and 59 and is suspended in elevated relation thereon by means of a latch 6| which takes the form of a vertically positioned yieldable member adapted to rest upon a protruding end of a supporting finger 62 thus holding the weight 60 in elevated position in the mechanism 24 on the guide rods .56 and 56. The supporting finger 62 forms a part ofthe pressure responsive release mechanism63 which mechanism comprises in part the subject matter of U. 8. Patent No. 2,099,069 of November 16, 1937 to E. A. Lowe, et al.; wherein its complete structure and operating principles are adequately set forth. It is therefore well known in the art. In order to simplify the present disclosure, the pressure responsive release mechanism 63 and its structure .are not herein deribed, claimed or illustrated, as they are vadequately set forth in the above mentioned patent. In the present disclosure, a pneumatioimpulse originated by the pneumatic impulse originating device 26 is conveyed to the pressure responsive release mechanism in the actuating mechanism 24 by means of the tubular connection 32. The pneumatic impulse causes the movement of a 7 pressure sensitive diaphragm in the pressure responsive release mechanism 63 which movement permits a partial rotation of a milled shaft 64 which in turn permits a lever 65 to move and through a system of levers 66, Bland 68 also permits a latch lever 66, which carries the supporting finger 62 as a part thereof, to rotate in a clockwise direction about apivota'H) thereby. allowing the weight 60 to fall. In operation, as described in the above mentioned patent to Lowe e't 2.1.; and in the present adaptation, the partial rotation of the latch lever 69 about the pivot 16 comprises the complete movement upon which the release of the weight 66 depends. In the present'disclosure as shown in Figure 3, therelease mechanism 63 has been modified slightly with respect to the placement of certain levers, particularly the reseating levers thereof which have been moved to one side of the release mechanism 63 and, in so doing, a'spring H has been substituted for a weight heretofore used to activate the lever shaft 66 of the mechanism; In order that the lever 65 may be moved to're-- set position as-shown in dotted lines Figure 3," an extended lever HA has been positioned on the lever shaft 66 and arranged so-that a reseating finger '12 may be engaged therebeneath to' elevate the extended lever HA and reseat finger 12 extends outwardly through a flexible" diaphragm 13 and terminates in a connection 14 which, as-is illustrated in Figure 3, has attached thereto a reseat handle I5. 'I'he reseat handle 15 is shown in detail in Figure 2 of the drawings. In operation, the reseat handle 15 is moved downwardly which causes the innermost end'of the reseating finger 72 to move the extended lever HA upwardly thus causing the lever to move into reseat position.

By referring again to Figure 3 of the drawings, it will be seen that the tubular connection 32, enters a junction box '16 at the uppermost portion of the actuating mechanism 24 and passes downwardly therefrom connecting with the appropriate portions of the pressure responsive release mechanism 63 so that the operation heretofore described may take place upon the introduction of a pneumatic impulse into the mechanism 63 through the tubular connection 32.

By referring to Figure 4 of the drawings, a cross sectional elevation of a pneumatic heat actuated device 2i may be seen to comprise a pair of hemispherical shells l1 and 11A placed in opposed relation and clamped together around their rims 16 so as to form an air tight. chamber. A tube 79 is introduced into the air chamber thus formed which tube 19 communicates with a fitting 86 which in turn is provided with an opening to the atmosphere which is normally closed with a removable plug 6|. The fitting 60 is also in communication with the pneumatic impulse conducting tubing 22 which as heretofore described in connection with Figure 1 communicates with the gas releasing mechanism l6. The several portions of the heat actuated device it are assembled upon a mounting bracket 82 which bracket 82 also carries a protective cage 83 positioned about the hemispherical shells 11 and HA.

It will thus be seen that a rapid increase in temperatures in fire zones protected by the sprinkler system will cause a pneumatic impulse to be originated by the heat actuated device 2| which will be conveyed by means of the tubes 19 and 22 back to the gas release mechanism l6 where it will serve to actuate the same and cause a release of compressed gas from the cylinder l5 into the pressure tank l3. Only a limited number of the pneumatic heat actuated devices 2| may be placed in communication with a single tubular connection such as indicated by the numeral 22 as a large number of the heat actuated devices communicating with a single tube will merely equalize pressures originating in one or more of the devices which will serve to nullify the action desired. In order to use a number of groups of heat actuated devices with separate and distinct tubular connections communicating with the gas release mechanism 16, a mercury check assembly such as illustrated in Figures 5 and 6 of the drawings is necessary. It is interposed between the pneumatic impulse conducting tubes and'the gas release mechanism [6. By referring to Figures 5 and 6 of the drawings, it will be seen that pneumatic impulses are conveyed to the mercury check assembly illus M trated through the tubing 22 and communicate communicating channel 87 and the lowermost portions of the chambers 85 and 88 contain a liquid check .such as mercury which is of an amount sufficient. to offset and to overcome minor impulses from the heat actuated devices 2| attached to and communicating with the tubular connection 22 and thus to prevent them from entering the chambers 88. By referring to the vertically positioned chamber 88, it will be seen that a horizontally positioned manifold chamber 83 communicates therewith and with each of the several other chambers 88 comprising the mercury check assembly so that pneumatic impulses introduced into any one of a number of the fittings 84 and the chambers 85 will, after suitably displacing the mercury check, pass into the horizontal manifold chamber 89 and thereby be placed in communication with a fitting!!!) which in turn is attached to and communicates with a tube 9| which communicates with the actuating portions of gas release mechanism IS. The mercury checks overcome minor impulses originating in the heat actuated devices 21 due to the fact that such minor impulses are incapable of sufficiently displacing the mercury to enable the impulse to pass through the check, into the horizontally positioned chamber S53 and ther by communicate through the tube 9| with the pressure responsive release upon which the action of the valve depends. The various groups of heat actuated devices 2! which may be used with the device of the invention are grouped by connection to the mercury check assemblies. In the event of a number of groups of heat actuated devices 2|, additional mercury checks are used which are positioned in separate cabinets adjacent the valve structure. The net result of such an arrangement is to reduce the incoming pressure conveying tubes 2.2 to a relatively small num bar which can be accommodated within the valve structure itself as shown. The impulses, therefore, may have passed through one or more mercury check assemblies before reaching the pressure responsive mechanism which actually releases the valve. In each of the mercury check assemblies the horizontal manifold chamber 89 receives the impulses from the several incoming pneumatic impulse conveying tubes 22 and connects them, when they have passed the individual mercury checks, with the tube 95 which in turn communicates with the pressure responsive release mehanism.

By referring now to Figures 1 and 7 of the drawings, it will be seen that a pneumatic impulse originating device 26 communicates with the compressed gas conveying connection H and is, therefore, adapted to receive the compressed gas when the same is released by the compressed gas release mechanism It. The pneumatic impulse originating device is illustrated in cross sectional detail in Figure l and by referring to the same it may be seen to comprise a pair of body members 92 and 93 affixed to each other in an opposed manner, at their edges, and so that they support between them a double diaphragm assembly 94 and a spacer 95. An orifice centrally located in the body member 93 is indicated by the numeral 98 and is adapted to 'be placed in communication with the fitting l8 heretofore described so that the compressed gas flowing there through may enter the body member at so as to move the diaphragm assembly 9 2 upwardly and obviously create a pneumatic impulse inthe area defined by the body member 92. In crdertliat the pneumatic impulse thus originated may be 7s ing a stud, 93 positioned on an opposing portion of the diaphragm assembly 94, there is a coil sprint; I89, which serves to maintain the diaphragm assembly 94 in depressed condition therefore insuring the origination of an adequate impulsein the area thereabove when it is deflected upwardly bycompressed gas pressure. I

It will be obvious to those skilled in the art that certain modifications to the specific form of the invention illustrated in Figure 1 are not only possible but desirable under some circumstances. For example, .the mercury checks heretofore described may be omitted from the gas pressure release mechanism 16 if a minimum of heat actuated devices 2| are utilized.

A further modification is possible in connection with the actuation of the gas releasing mechanisrn 1'6 such modification comprises the utilization of electric thermostats such as are Well known in the art and which electric thermostats close 'a' circuit which in turn actuates the gas release mechanism I6.

Other modifications obviously possible and desirable constitute the substitution of a pressure actuated electric switch for the pneumatic impulse originating device 23' and the connection therewith by means of an electric circuit of a modified-form of the automatic valve 23 and act'uating mechanism 24, the modification comprising" an electricallyactuated device such as is illustratedin Figure 8 of the drawings.

i In Figure 8 which is a side elevation similar in most respects to Figure 3 of the drawings heretofore described, an auxiliary supply control valve body is indicated by the numeral IDI and is provided with an actuating mechanism box I02. Positioned in a vertical portion of the mechanism box Hi2 there are a pair of guide rods I03 and H14, the guide rod I03 being comparable to the guide rod 59 heretofore described and the guide I04 being comparable to the guide rod 56 as heretofore described, Positioned on these guide rods and movable vertically thereof there.

is a weight Hi5 which conforms in exact detail with the weight 60 heretofore described,v the weight H15 being suspended in elevated relation by means of a latch I06 which takes the form of a vertically positioned yieldable member and is positioned on the projecting end of a supporting finger 101 thus holding the weight I05 in elevated position in the mechanism box I02. The weight N15 is adapted upon falling, after being released by movement of the supporting finger I01, to actuate mechanism in exact detail with that shown in Figure 2 of the drawings and heretofore described, wherein the movement of thefalling weight is used .to unlatch the clapper 31 of the valve. In the present modification, the weight in fallingstrikes a latch arm I08 which in turn is engaged with a latch link and latch (not shown) which serves to hold a clapper (not shown) in normally closed position.

from the secondary supply source associated therewith to the riser of the'sprinkler system, upon the pressure tank sprinkler systems going into operation in controlling a fire, an electrically actuated solenoid I09 is positioned in the mechanism box I02, an actuating member thereof being indicated by the numeral I I0, is positioned in operative relation to the lowermost end of a trigger member Ill. The trigger member III is pivoted to the mechanism box I02 by means of a pivot H2 and has a keeper portion H3 formed thereon which is adapted to retain partially thereinunder' a bar H4 formed on an upwardly extending arm H5 which in turn forms a portion of the supporting finger structure I01, the whole of which is pivoted to the mechanism box I02 by means of a pivot H6. Positioned in the mechanism box I02 and above the construction just referred to, there is a transformer and a relay unit- II! to which wire connections H8 are made, for supplying electric current. The transformer and relay unit H1 is connected to the solenoid H19 by means of circuit wires H9. In order that the modified form of valve and actuating mechanism may be employed in place of the valve 23 and mechanism 24 shown in Figure 1 of the drawings, an electric connection indicated in Figure 8 by the numeral I20 is substituted for the tubular connection 32, the same communicating with a pressure actuated electric switch substituted for the pneumatic impulse originating device 20 heretofore described. When the member Ill] is drawn up the weight I05 causes the arm H5 and the finger Hi! to move in a clockwise direction thus allowing the weight to fall and release the clapper of valve I0 I It will thus be seen that a deluge or preaction type of sprinkler system has been designed that will furnish adequate sprinkler protection for such occupancies as the same may be indicated for. The pressure tank portion of the system as well as the auxiliary fluid supply connection being controlled by heat actuated devices either pneumatic or electric positioned in the area being protected. When formed as a deluge system,

the sprinklers I2 are open so that fire extinguishing fluid forced from the tank l3 and subsequently, when the pressure subsides, from the secondary supply source 25, will flow outward from the open sprinklers I2 immediately, thus giving the desired deluge effect. When formed as a preaction sprinkler system, closed sprinklers are employed, the heat actuated devices 2i bringing the system into operation to the extent only of delivering fire extinguishing fluid from the tank and subsequently from the secondary supply source to the closed fused sprinklers, the actual opening in sprinklers depending upon the local fire conditions. In either form of system, an alarm, either water motor or electric, may be given as illustrated in Figure 1 by the provision of a pressure actuated electric switch lzl or a water motor connection I22 both of which communicate with the riser ID of the deluge or preaction pressure tank sprinkler system with secondary supply.

I claim:

1. In a fire extinguishing system including a tank for containing fluid, conducting pipes communicating therewith, sprinklers on said pipes, means for establishing pressure in the said supply tank to force the contents therefrom, the said means comprising a compressed gas source and a releasing mechanism therefor, pressure generating devices in the fire zone, means whereby the said devices actuate the said releasemechanism, a pneumatically actuated valve connecting the said fluid conducting pipes with a secondary fluid supply source and means extending from the said valve to the said releasing mechanism for actuating the said valve when the said releasing mechanism operates.

2. In a pressure tank sprinkler system installation for controlling and extinguishing fires including a tank for containing fluid and distributing piping containing air at atmospheric pressure and having sprinklers arranged to apply fire extinguishing fluid over the area where a fire may arise, and means for establishing pressure in said tank so as to force the fluid contents therefrom through the said sprinklers, said means including a suitable pressure source and releasing mechanism therefor connected with and responsive to heat actuated devices located in the fire zone; a valve controlling the admission of fire extinguishing fluid from a secondary fluid source to said piping and provided with restraining means for holding the said valve in closed position, a trip device operating on said restraining means to free said valve, and means extending from said release mechanism to said trip device for operating the valve upon actuation of the trip device 3. In a fire extinguishing apparatus including a fluid filled pressure tank, and a pressure source therefor, release means for releasing pressure from the said source into the said tank, thermostats in the fire zone for actuating said release means, distributing pipes in communication with said tank, and sprinklers on said piping, a secondary supply source comprising a connection between said pipes and a suitable fluid supply; a valve controlling the admission of the secondary fluid supply to the said piping and sprinklers, means whereby the said thermostats actuate the said release means to release pressure from the said pressure source into the tank and means whereby pressure from said source opens the said valve.

4. In a fire extinguishing system including a pressure tank, a pressure source, distributing piping, and heat sensitive devices in the fire area, the combination of dual fluid sources one being the pressure tank and the other being a city water supply connection, and dual release mechanisms controlling the same, one of said release mechanisms comprising a compressed gas release device for releasing pressure from said pressure source into said pressure tank upon the outbreak of fire in the area supervised by the sprinkler system and means whereby the said heat sensitive devices actuate the said release mechanism, the other release mechanism comprising means whereby an automatic valve controlling the said city water supply connection is opened by gas pressure from said pressure source.

HARRY N. RIDER. 

